The Giants defeated the Browns, six games to four, capturing their first World's Championship Series.
Over the offseason, the American Association's New York Metropolitans folded, and saw them replaced by the newly enfranchised Kansas City Cowboys.
American Association Opening Day took place on April 18 featuring all eight teams, while National League Opening Day took place on April 20, also featuring all eight teams.
The American Association would see its final day of the regular season on October 15 with a game between the Cleveland Blues and Philadelphia Athletics, while the National League would see its final day of the season on October 13, featuring all eight teams.
The 1888 season saw the following rule changes: An asterisk (*) denotes the ballpark a team played the minority of their home games at Blue laws restricted Sunday activities in several localities, causing several teams of the American Association (which was informally referred to as the "Beer & Whiskey League" due to its openness on alcohol, compared to the National League) to play at ballparks in a different locality.